Pneumatic jack



4 Sheets-Sheef 2 March l0, 1925 J. L. STRANDBERG ET AL PNEUMATIC JACKFiled sept. 12, 1923 W'Z'Zzss,

March l0, 1925.

, I 1,528,857 J. L. s TRANDBERG Er AL,

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Filedfse t. 1925' March 1o, 1925. l 1,528,857

l IJ. L. STRANDB'ERG ET AL PNEUMATIC JACK Filed Sept. 12, 1925 4Sheets-Sheet 4 Patented Mai'. 10, 1925. p

ffUzNiTEfD STAT-@Es JOHN L. STRANDBERG f'AND E11ans IE. tr.Broil/rianne; or Knaiis'as f crrv, "Mrssoiinr :NEUMATIC JACK.

. Application mea september 12, 1923. 'sriainosesaa'ia andfLixns J.BLoiunEnmcitizens of the United `'States."residing kat Kansas City, inthe county ot Jackson and State ofMissoui'i, have Vinvented certain newand useful Im'- provementsin `:Pneumatic Jacks, of which 'the followingis a` specification.

In carrying outthe present invention it is our purpose to provide apneumatic jack "for use .primarily in conjunction with the slow raisingof movable concrete forms that is a substantial improvement overthepneumatioijack shown and described. in our copending applicationtiled July 21st, 1923, and bearing Serial Number 652,961.

In this copending=application there'is set forth a pneumatic jack toruse inthe slow raising of movable concrete formsthat inj cludes-acylinder within which isf rectilinearly movable a piston adapted to be*forced downwardly withinV the cylinder by 'air pressure. This cylinderisoperatively connected to the concrete form; to be slowly raised andmoved upwardly upon a climbing rod when air is injectedinto saidcylinder. The piston during-the l'upst-roke of; the cylinder is adaptedto be operatively connected to said climbing rod-for preventing thedown-,stroke of t-heipistonupon the climbing rod. After the concrete form hasbeen 'raised to the limit of movement of the jack the cylinder itself isoperatively connected mechanicallyto saidclimbing rod andthe pistonreleased mechanically f therefrom and forced mechanically up upon saidrod and within the upper end of the cylinder whereby 'the operation ofthe jack may be repeated.

Theprimary object of this, our present invention, is to-provide suchafpneumaticj ack wherein automatic means is provided vfor theconnectingand disconnecting 'of the cylinder to and rfrom said rod,together with 'automatic means for connecting and disconnect ing saidpiston to and from saidrod as well as means 'for automatically returningthe piston to its initial position within the cylindery for allowing theoperation of the jack to lbe repeated.

An additional object of this invention is to provide'suchrapneumatic'jack that includes these automaticfeatures wherein the same,Vmay be: manufactured and operated 'at .acost but slightlyfgreater thanthe type of jacksetforthfin; the above mentioned oo- ;pendingapplication.;

Yetiy another .obj ectis the yprovision ,of'such of ourimproved.jack,the` elements thereof in theirnormal inoperativepositions,

Figure 2 is a front elevational view thereof,

Figure 3 is a detailed vertical cross section ot our iinprovedfjack, thefparts also being shown in their normal inoperative positions,

Figure 4 is a Y. detailed vertical section taken substantially upon the`line 4 4 ,of

Figure l, for more clearly disclosing the upper clampelenient of ourimproved jack, Figure 5 is -a longitudinal section of this i clampelementL taken substantially upon lthe linel 5 5 of FigureV 4, j

Figure 6-"isa side elevational view of one of the clamping jaws per seemployed in conjunetionwith thejupper andlower clamp elements of ourpneumatic jack,` and Figure 7 is ank elevational view ot one endthereof. Y,

, With specific reference to the drawings, our improved,pneumatic jackcomprises a relatively large cylinder 5 opened at its lower endl andformed centrally with an open endedtube 6 rthrough which isfreelymovable kthe well known climbing rodv 7 that isemployed in conjunctionwith-jacks specifically used in theslow raising of'movable concretevforms. .The interior of this cylinder 5 is formed adjacent Yits upperend with a shoulder 8 for `-limiting tlieupward sliding movement of ar-piston` 9 that is formed; upon the upper end of a hollow rod .10.-disposedjfor sliding movement upon the beforementioned open ended tube 6formed centrally within Isaid cylinder 5. In coinmunication with theupper end of this cylinder 5 isa `C.onfliwuessel air inlet pipe 1l, thathas;V communication at itsopposite .end

with a suitable source of compressed air supply, the upper end of thiscylinder being also equipped with an exhaust valve in the form of a petcock 12 that may be regulated for controlling the exhaust of the airfromthe cylinder during the upstroke of the piston in a mannerhereinafter set forth. Adjacent the lower end of this cylinder, the sameis equipped with discharge openings 18 whereby when the same areuncovered by the piston 9 on its downstroke the air will be permitted todischarge from the cylinder and consequently prevent said piston 9 frombeing totally discharged therefrom.

Upon the upper closed end of said cylinder 5 is an automaticallyoperating climbing rod clamp designated generally 14 which clampcomprises a casing including side walls 15 inter-connected at theirupper and lower ends by integral top and bottom walls 16 and 17respectively that are formed centrally with alined openings 18 for thefree passage of the before mentioned climbing rod 7. The bottom wall 17of this clamp casing is formed at its opposite ends with verticalopenings 19 through whichv extend the upper screw-tlneaded ends of rods20, the upper end of the before mentioned cylinder 5 being formed atpoints beneath the openings in said bottom wall, with laterally directedlugs 21 which are also provided with openings for the passage of saidrods 2O these rods extending downwardly and being operatively connectedto the movable concrete form, not shown, in a manner similar to thatshown and described in our co-pending application above referred to.These rods are maintained connect-ed to said clamp casing and to saidcylinder 5 through the medium of j amb nuts 22 and 28, Figures 1 and 4.

Loosely pivotally disposed between said side walls 15, 15 of theclimbing rod clamp casing and on opposite sides of the alined openings18, 18 within the top and bottom walls 16 and 17 thereof, aregravitational clamps 24 that are weighted at their outer ends as at 25for normally maintaining their inner toothed edges 26 in engagement withsaid climbing rod 7, each of these clampsbeing formed with slots 27 forthe purpose of lightness.

Beneath the cylinder 5 and freely slidable in an upward direction uponthe above mentioned climbing rod 7 is another automatic climbing rodclamp member designated generally 28 which is as clearly shown inFigures 1, 2 and 8, positioned at direct right angles to the firstmentioned automatic climbing rod clamp element designated generally 14.The construction of this automatic climbing rod clamp element 28 issubstantially similar to the construction of the clamp element 14, thesaine coinprising a casing .including side walls 29 integrally joinedtogether by top and bottom. walls 8O and 81, respectively, which topandy bottom walls are formed centrally with alincd openings for the freepassage of said climbing rod while pivoted between said side walls 29are loosely pivoted clamping jaws 88 that are identical in constructionto the clamping jaws 84 of the clamp element 14.

The opposite ends of the top wall 8O of said clamp casing is formed withsubstantially L-shaped slots for receiving the lower hooked ends 88 ofrelatively strong retractilc springs 84 the ends of each of thesesprings boing connected to laterally extending lugs 85 formed upon theupper end of the cylinder 5 between the before mentioned lugs 21 throughthe medium of bolt and nut connections 86. ln view of these retractilesprings 84 the different parts of this automatic pneumatic jack aremaintained in the positions more clearly shown in the detailed crosssectional view, Figure 8.

1n actual practice the climbing rod 7 ris positioned properly withrespect to the movable concrete form to be slowly raised, it being ofcourse understood that the elements of our improved pneumatic jack areto be positioned thereon and inter-connected as shown in said crosssectional view, Figure 8. After the rods 20, 20 have been connected attheir lower ends to the concrete form and it is desired to slowlyraisethe same, air is injected into the upper end of the cylinderthrough the compressed air pipe 11. The aws 88 in the lowermost clampelement 28 will tightly grasp the climbing rod 7 and thereby prevent anydownward movement of this clamp element or the other parts of theinvention. The air pressure on entering the cylinder 5 above the piston9 will cause this piston to contact with the top wall 8O of thelowermost clamp element, and in view of the fact that movement of thisclamp element is prevented by the jaws 88 the cylinder 5 will slowlyrise for consequently carrying upwardly the concrete form through themedium of the connection rods 20, 20. The upward movement of saidcylinder 5 will expand the springs 84 the tension of these springshowever, being such as not to overcome the air pressure within thecylinder and upon a continued upward movement of this cylinder, the airport 18 adjacent the lower end thereof will be uncovered by the piston 9for thereby allowing the escape of the air and preventing further upwardmovement of the cylinder. After said cylinder has reached its limit ofupward movement, the compressed air supply is turned off after which thepet cock 12 may be opened to a desired degree, whereupon the springs 84in assuming their normal positions will consequently draw upwardly uponthe automatic clamp element 28 and return the piston 9 to its normalposition within the cylinder for allowing the operation to be repeated.

IVe have described our improved automatic pneumatic jack as beingemployed in conjunction with the slow raising of mov# able concreteforms, it is nevertheless, to be understood that we do not wish to limitthis improved jack to such a` use, as in the future practice of theinvention the same may be employed in conjunction with the hoisting o'lfnumerous devices. Y

In view of the above description when considered in conjunction with theaccompanying drawings, the detailed operation together with numerousadvantages of a pneumatic jack of this character will be at onceappreciated by those skilled. in the art, and even though we have hereinset forth that this jack consists of certain detailed structuralelements, it is nevertheless to be understood that departures may bemade from the different elements of this invention, without deviatingfrom the spirit and scope of the n appended claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is :-V

l. In a hoisting device of the character set forth, a guide, a jackslidable upon said guide and comprising upper and lower relativelydisplaceable members, means for facilitating the displacement of saidmembers, means for preventing the movement of the lower member in onedirection when the upper member is moving in an opposite direction,means :tor moving said lower member in an upper direction when saidupper member has stopped, means for holding said upper member againstdownward movementas said lower member is being moved upwardly, saidmeans for moving said lower member upwardly comprising springconnections between said upper and lower members.

2. A device of the class described comprising a pair of relativelyslidable interfitting members movably mounted on a rod, interconnectedgripping means movable on the rod in one direction, for preventingmovement of the members in the opposite direction and adapted tonormally operate the members to hold them in a predetermined relation,and means for eiiecting a relative movement between said members fromsaid predetermined relation.

A device of the class described comprising a pair of relatively slidableinterfitting members movably mounted on a rod, gripping means for eachof said members mounted on the rod for securing said members againstmovement on said rod, means for connecting the gripping means for eachmember normally operable for moving and holding said members in apredetermined relation, and fluid actuating means for producing arelative movement of the members.

u 4. A device of the class described, comprising a pair of relativelyslidable intertitting members movably mounted on a rod, gravity actuatedgripping means associated with each member and mounted for grippingaction in one direction on saidvrod, and means for producing a relativesliding movement of the members.

5. A device of the class described, comprising a pair of relativelyslidable interfitting members movably mounted on a rod, gravity actuatedgripping means mounted for one way movement on said rod havinV a casingprovided with a pair of pivote gripping pawls at opposite sides of therod, adjacent ends of which are formed for gripping said rods and theopposite ends of which are formed with weighted portions adapted tonormally actuate said pawl to grip said rod, and means for producing arelative sliding movement of the member.

6. A device of the class described, including a pair of relativelyslidable interitting members movably mounted on a rod, a pair ofgripping means mounted for oneway movement on said rod, and carried byone of said members, one of said gripping means being resilientlyconnected to said member and engaging the other member adapted forpreventing movement of the last mentioned member on the rod, and meansfor effecting a rela-tively slidable movement of said member.

7 A device of the class described including a cylinder slidable on itsrod, a piston slidable in said cylinder, a gripping member mounted onone end of said cylinder and said rod, and adapted to grip said rod forpreventing a movement of the cylinder on the rod, a gripping membermounted on the rod beyond the opposite end of the cylinder, and adaptedfor engaging the piston to prevent movement of the piston relative tothe rod, spring members connecting the cylinder and the last mentionedgripping member, for normally pulling said gripping member toward thecylinder, and uid actuating means for moving the piston in the cylinder.

In testimony whereof we aix or signatures.

JOHN L. STRANDBERG. LARS E. J. BLOMBERG.

